The ornamental design for puzzle, as shown and described.
FIG. 1 is a perspective view showing my new design for a puzzle;
FIG. 2 is a perspective view showing the puzzle board and puzzle pieces in FIG. 1 in a separated state;
FIG. 3 is a top plan view of FIG. 1;
FIG. 4 is a perspective view showing the design in association with an alternate set of puzzle pieces;
FIG. 5 is a perspective view showing the puzzle board and puzzle pieces in FIG. 4 in a separated state;
FIG. 6 is a top plan view of FIG. 4;
FIG. 7 is a perspective view showing the design in association with another alternate set of the puzzle pieces;
FIG. 8 is a perspective view showing the puzzle board and puzzle pieces in FIG. 7 in a separated state; and,
FIG. 9 is a top plan view of FIG. 7.
The sides and bottom of the puzzle are substantially flat and unornamented. The puzzle pieces shown in broken lines are for illustrative purposes only and form no part of the claimed design.